Hydrogenation catalyst as well as preparation method and application thereof

Abstract

The invention provides a hydrogenation catalyst and a preparation method and application thereof.The preparation method comprises the steps that after an aluminum oxide raw material and a forming additive are mixed, kneaded and formed, first drying is conducted, and an aluminum oxide carrier intermediate is obtained; immersing the alumina carrier intermediate in an ammonium bicarbonate aqueous solution for heat treatment, filtering the material subjected to heat treatment, and sequentially carrying out second drying and first roasting on the solid material obtained by filtering to obtain an alumina carrier; wherein the heat treatment temperature ranges from 70 DEG C to 90 DEG C, and the heat treatment time ranges from 4 h to 10 h; and dipping the alumina carrier in a metal aqueous solution, and then successively carrying out third drying and second roasting to obtain the hydrogenation catalyst. The specific surface area of the hydrogenation catalyst is increased, and the desulfurization and denitrification performance of the hydrogenation catalyst is improved.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation, specifically to a hydrogenation catalyst, its preparation method, and its application. Background Technology

[0002] Petroleum reforming processes require reforming catalysts, which are typically precious metal catalysts and highly sensitive to impurities. Petroleum (reforming feedstock) usually contains a certain amount of unsaturated olefins and impurities such as sulfur, nitrogen, and arsenic. This not only affects the performance of the reforming catalyst but also hinders the long-term stable operation of the catalytic reforming unit. Therefore, it is necessary to pre-hydrogenate the petroleum (reforming feedstock) to ensure that its impurity content meets the quality requirements for reforming feedstock, thereby guaranteeing the full performance of the reforming catalyst and achieving long-term stable operation of the catalytic reforming unit.

[0003] Impurities such as nitrogen, sulfides, and olefins in petroleum with a nitrogen content below 5 μg / g (such as straight-run naphtha) are relatively easy to remove. During the pre-hydrorefining process to reduce the sulfur and nitrogen content in the refined naphtha to less than 0.5 μg / g, the pre-hydrorefining process is relatively mild, with hydrogen partial pressure generally not exceeding 4.0 MPa, mostly between 2.0 and 3.0 MPa. However, petroleum with a nitrogen content above 10 μg / g (such as straight-run naphtha) is difficult to meet the requirements for reforming feed under the aforementioned mild pre-hydrorefining process. Therefore, without modifying the pre-hydrorefining process and equipment, only by improving the low-pressure hydrodenitrogenation activity of the hydrotreating catalyst can the refined naphtha after pre-hydrorefining meet the requirements for reforming feed.

[0004] For example, patent document CN201510634380.9 discloses a catalyst comprising the following chemical components: WO3 or MoO3, CoO or Fe2O3, NiO or CuO, one or more of Na2O, K2O, MgO or CaO, La2O3 or Ce2O3, with the balance being Al2O3. In the catalyst support preparation process, this patent involves ultrasonically treating a slurry mixture of aluminum-containing raw materials and porous carbon materials to obtain a modified material, giving it higher strength, a larger specific surface area, and a larger pore volume. This allows for a more uniform distribution of the catalyst's active components on the support. The catalyst exhibits strong adaptability to process conditions and high hydrodesulfurization and denitrification activity, capable of processing straight-run naphtha feedstock with a nitrogen content of 10 μg / g under a pressure of 2.0 MPa and a volume hourly space velocity of 10 h⁻¹. -1 The concentration can be reduced to below 0.5 μg / g under certain conditions. However, this catalyst involves many components and its preparation process is relatively complex.

[0005] Patent document CN201110191663.2 discloses a hydrogenation catalyst and its preparation method. The catalyst uses silica-containing alumina as a support, molybdenum and cobalt as active components, and boron and alkali metals and / or alkaline earth metals as additives. The silica-containing alumina support precursor is boehmite containing amorphous silica and aluminum. It is obtained by first preparing an amorphous silica-alumina slurry and a boehmite slurry, then mixing, aging, filtering, and drying these two slurries. The alkali metals, alkaline earth metals, and boron (boric acid) are added to the silica-containing alumina support before the addition of molybdenum and cobalt. The catalyst is prepared at a pressure of 2.5 MPa and a volume hourly space velocity of 8 h⁻¹. -1 Under these conditions, the nitrogen content of the raw material, which is 2.46 μg / g, can be reduced to below 0.5 μg / g. The catalyst in this patent processes raw materials with a low nitrogen content, not exceeding 5 μg / g, falling within the scope of traditional reforming feedstock pretreatment. It exhibits good hydrogenation effects for reforming feedstocks with a nitrogen content not exceeding 5 μg / g.

[0006] Patent document CN201210290784.7 discloses a method for preparing a hydrogenation pretreatment catalyst for reforming feedstock. The catalyst composition is WO3, NiO, CoO, MgO, K2O, TiO2, with the remainder being alumina. Commercially available boehmite powder, metatitanic acid, a potassium salt (one of potassium nitrate, potassium carbonate, or potassium acetate), a peptizing agent (nitric acid aqueous solution), and an extrusion aid (one of methylcellulose or guar gum) are mixed and kneaded until a plastic state is achieved. The mixture is then extruded, dried, and calcined to obtain a K-Al2O3-TiO2 composite support. A W-Ni-Co-Mg co-impregnation solution is prepared at room temperature, and then saturated impregnation, drying, and calcination are performed on the above support to obtain the hydrogenation pretreatment catalyst. The reaction pressure is 2.7 MPa, and the space velocity is 8.0 h⁻¹. -1 Under these conditions, the nitrogen content of raw materials with a nitrogen content of 5.2 μg / g can be reduced to below 0.5 μg / g. The nitrogen content of the raw material processed by the catalyst in this patent is 5.2 μg / g, which falls within the scope of traditional reforming feedstock pretreatment.

[0007] Patent document CN201911047998.X describes a reaction at a pressure of 2–5 MPa, a temperature of 160–320 °C, and a volume hourly space velocity of 1.8–8 h⁻¹. -1 Under the following conditions, a hydrorefining catalyst, hydrogen, and a low-quality feedstock oil are contacted. The hydrorefining catalyst contains inorganic refractory components, an active component, and a carboxylic acid. The inorganic refractory components contain at least one of silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, and titanium oxide, and some of the active components. The low-quality feedstock oil has a sulfur content ≥600 μg / g and a nitrogen content ≥10 μg / g. Examples report conditions with a feedstock nitrogen content of 32.2 μg / g, a reaction pressure of 4.0 MPa, and a volume hourly space velocity (VHSV) of 3 h⁻¹. -1Under these conditions, the nitrogen content in the product is less than 0.3 μg / g. This invention's method can hydrotreat oils containing high sulfur and high nitrogen impurities to produce refined oils that meet the requirements of reforming feedstocks, thus broadening the range of reforming feedstocks. However, the hydrotreating catalyst involved in this method has a high metal content, resulting in high catalyst costs.

[0008] Improving the hydrodenitrification performance of hydrogenation catalysts has become a research hotspot in the field. Summary of the Invention

[0009] This invention provides a hydrogenation catalyst, its preparation method, and its application, which helps to increase the specific surface area of ​​the hydrogenation catalyst and improve its desulfurization and denitrification performance.

[0010] This invention provides a method for preparing a hydrogenation catalyst, comprising: mixing and molding an alumina raw material with a molding aid, followed by a first drying to obtain an alumina support intermediate; immersing the alumina support intermediate in an ammonium bicarbonate aqueous solution for heat treatment, then filtering the heat-treated material, and then sequentially subjecting the filtered solid material to a second drying and a first calcination to obtain an alumina support; wherein the heat treatment temperature is 70–90°C, and the heat treatment time is 4–10 h; immersing the alumina support in an aqueous metal solution, and then sequentially subjecting it to a third drying and a second calcination to obtain the hydrogenation catalyst.

[0011] Optionally, the alumina raw material includes boehmite; and / or, the mass percentage of ammonium bicarbonate in the ammonium bicarbonate aqueous solution is 10% to 18%; and / or, the mass ratio of the ammonium bicarbonate aqueous solution to the mass of the alumina precursor intermediate is (1.3 to 3.6):1.

[0012] Optionally, the molding aid includes one or more of a binder, an extrusion aid, and a modifier, wherein the binder includes one or more of nitric acid, acetic acid, and oxalic acid, the extrusion aid includes guar gum powder, and the modifier includes one or more of ammonium fluoroborate, phosphoric acid, and silica sol.

[0013] Optionally, the first drying temperature is 100–120°C, and the first drying time is 4–6 hours; and / or, the second drying temperature is 100–120°C, and the second drying time is 4–6 hours; and / or, the third drying temperature is 100–120°C, and the third drying time is 4–6 hours; and / or, the first calcination temperature is 300–600°C, and the first calcination time is 4–6 hours; and / or, the second calcination temperature is 300–600°C, and the second calcination time is 4–6 hours.

[0014] Optionally, the process of immersing the alumina intermediate in an aqueous metal solution includes: immersing the alumina intermediate in an equal volume of an aqueous metal solution; and / or, the aqueous metal solution includes one or more of nickel, cobalt, molybdenum, and tungsten.

[0015] This invention provides a hydrogenation catalyst, which is prepared according to the method described above.

[0016] Optionally, the specific surface area of ​​the hydrogenation catalyst is 250–290 m². 2 / g, specific pore volume is 0.43~0.50cm³ 3 / g.

[0017] Optionally, in the hydrogenation catalyst, the mass percentage of cobalt is 1.5% to 3.0%, the mass percentage of molybdenum is 5.0% to 17.0%, the mass percentage of nickel is 1.0% to 5.0%, and the mass percentage of tungsten is 10.0% to 15.0%, based on metal oxides.

[0018] This invention provides an application of the hydrogenation catalyst described above in the hydrotreating of oil products.

[0019] Optionally, the nitrogen content in the oil is greater than or equal to 5 μg / g, and the sulfur content is greater than or equal to 600 μg / g.

[0020] This invention provides a hydrogenation catalyst, its preparation method, and its application. Ammonium bicarbonate is used as a hydrothermal medium to modify an alumina support intermediate, resulting in an alumina support with a fibrous microstructure. This helps improve the surface properties of the hydrogenation catalyst, increase its specific surface area, and thus increase the contact area between the reactants and the hydrogenation catalyst. Next, the fibrous alumina support is impregnated in a metal aqueous solution, and a metal (active metal) is loaded onto the alumina support. This allows for more uniform dispersion of the metal within the alumina support, promoting a more complete hydrogenation reaction. The hydrogenation catalyst prepared according to the above process has a high specific surface area and more uniform metal dispersion, resulting in high catalytic activity and excellent desulfurization and denitrification performance. Attached Figure Description

[0021] Figure 1 The image shows a scanning electron microscope image (5000x) of the hydrogenation catalyst CAT-1 from Example 1.

[0022] Figure 2 The image shows a scanning electron microscope image (50,000x) of the hydrogenation catalyst CAT-1 from Example 1.

[0023] Figure 3 The image shows a scanning electron microscope image (5000x) of the hydrogenation catalyst DB-1 in Comparative Example 1. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below. The specific embodiments listed below are merely descriptions of the principles and features of the present invention, and the examples are only for explaining the present invention and are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Traditional hydrogenation catalysts are ineffective in treating low-quality feedstock oils with sulfur content greater than or equal to 600 μg / g and nitrogen content greater than or equal to 5 μg / g. Current technologies often aim to improve the activity of hydrogenation catalysts by increasing the content of active metals, but this leads to increased production costs.

[0026] Based on this, embodiments of the present invention provide a method for preparing a hydrogenation catalyst, comprising: mixing and molding an alumina raw material with a molding aid, followed by a first drying to obtain an alumina support intermediate; immersing the alumina support intermediate in an ammonium bicarbonate aqueous solution for heat treatment, then filtering the heat-treated material, and then sequentially subjecting the filtered solid material to a second drying and a first calcination to obtain an alumina support; wherein the heat treatment temperature is 70–90°C and the heat treatment time is 4–10 h; immersing the alumina support in an aqueous metal solution, and then sequentially subjecting it to a third drying and a second calcination to obtain the hydrogenation catalyst.

[0027] According to the inventors' research and analysis: In the preparation system of this invention, the alumina support intermediate is first immersed in an ammonium bicarbonate aqueous solution and then heat-treated at 70-90°C. During the heat treatment, ammonium bicarbonate acts as a hydrothermal medium to modify the alumina support intermediate (hydrothermal modification), resulting in an alumina support with a fibrous microstructure. This improves the surface morphology of the alumina support, helps to improve the surface properties of the hydrogenation catalyst, increases its specific surface area, and thus increases the contact area between the reactants and the hydrogenation catalyst. Furthermore, immersing the alumina support with the fibrous structure in a metal aqueous solution can adjust the distribution of the metal (active metal), facilitating the dispersion of the metal in the alumina support. The more uniform metal content promotes a more complete hydrogenation reaction, which helps improve the low-pressure denitrification and desulfurization activity of the hydrogenation catalyst. It can be seen that the hydrogenation catalyst prepared according to the above process has a higher specific surface area, more uniform metal dispersion, and higher catalytic activity, exhibiting excellent desulfurization and denitrification performance. This hydrogenation catalyst can hydrogenate low-quality feedstock (reforming feedstock) with sulfur content greater than or equal to 600 μg / g and nitrogen content greater than or equal to 5 μg / g under mild conditions (e.g., lower reaction temperature and pressure). The hydrogenation treatment effect is good, ensuring that the hydrogenated feedstock meets reforming requirements, avoiding the high cost problem caused by increasing the metal content in the hydrogenation catalyst to improve its catalytic activity. Furthermore, the above preparation method requires fewer raw materials and has a simpler process.

[0028] In some embodiments, the alumina raw material includes boehmite.

[0029] Molding aids may include one or more of adhesive solvents, extrusion aids, and modifying agents.

[0030] The adhesive solvent may include one or more of nitric acid, acetic acid, and oxalic acid; the extrusion aid includes substances that facilitate the extrusion molding of the alumina carrier intermediate, specifically including guar gum powder; the modifying agent may include one or more of fluorine (F), boron (B), phosphorus (P), and silicon (Si), specifically including one or more of ammonium fluoroborate, phosphoric acid, and silica sol.

[0031] In addition, molding aids may also include citric acid and metatitanic acid.

[0032] The embodiments of this invention do not limit the specific method of the above-mentioned kneading molding or the amount of alumina raw material and molding aid. Conventional methods and amounts in the art can be used. For example, the alumina carrier can be prepared according to the following process: dissolve citric acid in deionized water, add a peptide solvent, and stir evenly to obtain a solution for later use; place the alumina material, metatitanic acid, and extrusion aid in a crucible, stir evenly to obtain a powder; then slowly add the above-mentioned solution for later use to the above-mentioned powder while stirring, and stir evenly to obtain a wet mixture; after extruding the wet mixture, perform a first drying to obtain an alumina carrier intermediate. Specifically, the above extrusion molding can be carried out by using a twin-screw extruder to extrude the wet mixture into a clover-shaped strip with a diameter of 1.8 mm (Φ1.8).

[0033] The temperature for the first drying step can be 100–120°C, and the drying time can be 4–6 hours.

[0034] In some embodiments, the mass percentage of ammonium bicarbonate in the aqueous solution is 10% to 18%, for example, 10%, 12%, 14%, 16%, 18%, or any combination thereof. In the preparation system of this embodiment, the aforementioned aqueous solution of ammonium bicarbonate can better modify the alumina support intermediate, forming an alumina support with a fibrous microstructure, further improving the surface properties of the hydrogenation catalyst, thereby increasing the specific surface area of ​​the hydrogenation catalyst and improving its desulfurization and denitrification performance.

[0035] In some embodiments, the mass ratio of the ammonium bicarbonate aqueous solution to the alumina precursor intermediate is (1.3–3.6):1, for example, 1.3:1, 2:1, 2.5:1, 3:1, 3.6:1, or any combination thereof. In the preparation system of this embodiment, the ammonium bicarbonate aqueous solution can better modify the alumina precursor intermediate, forming an alumina precursor with a fibrous microstructure, further improving the surface properties of the hydrogenation catalyst, thereby increasing the specific surface area of ​​the hydrogenation catalyst and improving its desulfurization and denitrification performance.

[0036] For example, the temperature of the heat treatment can be 70 to 90°C, such as 70°C, 75°C, 80°C, 85°C, 90°C or any combination thereof, and the heat treatment time can be 4 to 10 hours, such as 4 hours, 5 hours, 6 hours, 8 hours, 10 hours or any combination thereof.

[0037] In practice, the above heat treatment can be carried out in an open container, or the container can be covered without sealing. For example, an ammonium bicarbonate aqueous solution can be prepared in a beaker, and then the alumina precursor intermediate can be immersed in the ammonium bicarbonate aqueous solution before placing the beaker in a forced-air drying oven for heat treatment.

[0038] Understandably, after heat treatment, the heat-treated material needs to be cooled to room temperature before filtration.

[0039] The temperature for the second drying stage can be 100–120°C, and the drying time can be 4–6 hours.

[0040] The temperature for the first roasting can be 300–600℃, and the roasting time can be 4–6 hours.

[0041] The process of immersing the alumina intermediate in an aqueous metal solution includes: immersing an equal volume of the alumina intermediate in the aqueous metal solution.

[0042] In some embodiments, the aqueous metal (active metal) solution includes one or more of nickel (Ni), cobalt (Co), molybdenum (Mo), and tungsten (W).

[0043] The aforementioned aqueous metal solution is obtained by dissolving metal salts or metal oxides in water under acidic or alkaline conditions. For example, one or more sparingly soluble salts from basic cobalt carbonate, ammonium heptamolybdate or molybdenum trioxide (MoO3), nickel nitrate or basic nickel carbonate, or ammonium metatungstate are added to a certain amount of water and phosphoric acid and heated until dissolved. Then, easily soluble salts are added to form a homogeneous multi-component metal impregnation solution.

[0044] The temperature for the third drying stage can be 100–120°C, and the drying time can be 4–6 hours.

[0045] In embodiments of the present invention, a forced-air drying oven can be used to dry materials (e.g., first drying, second drying, and third drying).

[0046] The temperature for the second roasting can be 300–600℃, and the roasting time can be 4–6 hours.

[0047] In embodiments of the present invention, a muffle furnace can be used to roast the material (e.g., first roasting and second roasting).

[0048] This invention also provides a hydrogenation catalyst that can be obtained according to the above-described preparation method. This hydrogenation catalyst has a high specific surface area and excellent desulfurization and denitrification performance, making it suitable for hydrogenation desulfurization and denitrification under low-pressure, low-hydrogen-to-oil ratio conditions.

[0049] In some embodiments, the specific surface area of ​​the hydrogenation catalyst is 250–290 m². 2 / g, specific pore volume is 0.43~0.50cm³ 3 / g, with a good pore structure, exhibiting excellent desulfurization and denitrification performance.

[0050] The aforementioned hydrogenation catalyst may include catalytic active components such as CoMoNi or CoMoNiW. Based on the metal (active metal) oxides, the mass percentage (loading) of cobalt can be 1.5%–3.0%, the mass percentage (loading) of molybdenum can be 5.0%–17.0%, the mass percentage (loading) of nickel can be 1.0%–5.0%, and the mass percentage (loading) of tungsten can be 10.0%–15.0%. These metals are uniformly dispersed in the hydrogenation catalyst, giving it excellent desulfurization and denitrification performance.

[0051] This invention also provides an application of the above-mentioned hydrogenation catalyst in the hydrotreating of oil products.

[0052] In some embodiments, the above-mentioned oil products include straight-run naphtha.

[0053] Furthermore, the nitrogen content in the above-mentioned oil products can be greater than or equal to 5 μg / g, and the sulfur content can be greater than or equal to 600 μg / g. The hydrogenation catalyst of the present invention is suitable for treating the above-mentioned oil products with high nitrogen and sulfur content, and exhibits excellent desulfurization and denitrification performance.

[0054] The present invention will be further described below through specific embodiments and comparative examples. Unless otherwise specified, the reagents, materials and instruments used below are all conventional reagents, materials and instruments, all of which are commercially available, and the reagents and materials involved can also be synthesized by conventional synthetic methods.

[0055] The sources of some of the raw materials are as follows:

[0056] Phobospore: Shandong Wanlin Environmental Protection New Materials Co., Ltd.;

[0057] Nitric acid: Anhui Jinyueguan New Materials Co., Ltd., concentration greater than or equal to (≮) 65%;

[0058] Citric acid: Sinopharm Group, purity greater than or equal to 99.5%;

[0059] Metatitanic acid: Guangdong Wengjiang Chemical Reagent Co., Ltd., purity greater than or equal to 99.0%;

[0060] Ammonium bicarbonate: Tianjin Huasheng Chemical Reagent Co., Ltd., purity greater than or equal to 99.2%;

[0061] Silica sol: Dezhou Jinghuo Glass Co., Ltd., SiO2 content is 40%;

[0062] Examples 1 to 8

[0063] Example 1

[0064] This embodiment provides a method for preparing a hydrogenation catalyst, including:

[0065] 1) Dissolve 3g of citric acid in 95g of deionized water, then add 3g of nitric acid and stir until homogeneous to obtain a solution for later use; place 100g of boehmite, 10g of metatitanic acid, and 3g of guar gum powder in a crucible and stir until homogeneous to obtain a powder; slowly add the above solution for later use to the above powder while stirring until homogeneous to obtain a wet mixture; extrude the above wet mixture into clover-shaped strips with a diameter of 1.8mm (Φ1.8) using a twin-screw extruder, and then perform a first drying to obtain alumina carrier intermediate SRZ-0; wherein, the temperature of the first drying is 120℃ and the time of the first drying is 4h;

[0066] 2) Dissolve 22g of ammonium bicarbonate in 100mL of water under stirring to obtain an ammonium bicarbonate aqueous solution with a mass percentage of 18%; immerse 50g of alumina carrier intermediate SRZ-0 in 110g of the above ammonium bicarbonate aqueous solution for heat treatment (i.e., the mass ratio of the ammonium bicarbonate aqueous solution to the mass of the alumina carrier intermediate is 2.2:1); cool the heat-treated material to room temperature and filter it; then subject the filtered solid material to a second drying and a first calcination to obtain alumina carrier SR-1; wherein the heat treatment temperature is 70℃ and the heat treatment time is 6h; the second drying temperature is 120℃ and the second drying time is 4h; and the first calcination temperature is 500℃ and the first calcination time is 4h.

[0067] 3) An equal volume of alumina support SR-1 was impregnated in a CoMoNi metal aqueous solution, followed by a third drying and a second calcination to obtain the hydrogenation catalyst CAT-1. The CoMoNi metal aqueous solution was prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, and water. The third drying was carried out at 120°C for 4 hours, and the second calcination was carried out at 500°C for 5 hours. During this period, by controlling factors such as the concentration of metals in the CoMoNi metal aqueous solution, the loadings of CoO, MoO3, and NiO in the hydrogenation catalyst CAT-1 were 2.5%, 15.0%, and 1.5%, respectively.

[0068] Example 2

[0069] This embodiment is basically the same as Embodiment 1, except that:

[0070] In step 3), an equal volume of alumina support SR-1 is impregnated in a CoMoNi metal aqueous solution, followed by a third drying and a second calcination to obtain the hydrogenation catalyst CAT-2. The CoMoNi metal aqueous solution is prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, and water. Furthermore, by controlling factors such as the concentration of metals in the CoMoNi metal aqueous solution, the loadings of CoO, MoO3, and NiO in the hydrogenation catalyst CAT-2 are 1.5%, 17.0%, and 1.0%, respectively.

[0071] All other conditions remain unchanged.

[0072] Example 3

[0073] This embodiment is basically the same as Embodiment 1, except that:

[0074] In step 3), an equal volume of alumina support SR-1 is impregnated in a CoMoNi metal aqueous solution, followed by a third drying and a second calcination to obtain the hydrogenation catalyst CAT-3. The CoMoNi metal aqueous solution is prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, and water. Furthermore, by controlling factors such as the concentration of metals in the CoMoNi metal aqueous solution, the loadings of CoO, MoO3, and NiO in the hydrogenation catalyst CAT-3 are 2.5%, 13.0%, and 2.0%, respectively.

[0075] All other conditions remain unchanged.

[0076] Example 4

[0077] This embodiment is basically the same as Embodiment 1, except that:

[0078] In step 3), an equal volume of alumina support SR-1 is impregnated in a CoMoNi metal aqueous solution, followed by a third drying and a second calcination to obtain the hydrogenation catalyst CAT-4. The CoMoNi metal aqueous solution is prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, ammonium metatungstate, and water. Furthermore, by controlling factors such as the concentration of metals in the CoMoNiW metal aqueous solution, the loadings of CoO, MoO3, NiO, and WO3 in the hydrogenation catalyst CAT-4 are 1.5%, 5.0%, 2.0%, and 12.5%, respectively.

[0079] All other conditions remain unchanged.

[0080] Example 5

[0081] This embodiment is basically the same as Embodiment 1, except that:

[0082] In step 2), 18g of ammonium bicarbonate is dissolved in 100mL of water under stirring to obtain an ammonium bicarbonate aqueous solution with a mass percentage of 15%. 50g of alumina carrier intermediate SRZ-0 is immersed in 90g of the above ammonium bicarbonate aqueous solution for heat treatment (i.e., the mass ratio of the ammonium bicarbonate aqueous solution to the mass of the alumina carrier intermediate is 1.8:1). After the heat-treated material is cooled to room temperature, it is filtered. The filtered solid material is then subjected to a second drying and a first calcination to obtain alumina carrier SR-2. The heat treatment temperature is 90℃ and the heat treatment time is 6h. The second drying temperature is 120℃ and the second drying time is 4h. The first calcination temperature is 500℃ and the first calcination time is 4h.

[0083] In step 3), an equal volume of alumina support SR-2 is impregnated in a CoMoNi metal aqueous solution, followed by a third drying and a second calcination to obtain the hydrogenation catalyst CAT-5. The CoMoNi metal aqueous solution is prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, and water. Furthermore, by controlling factors such as the concentration of metals in the CoMoNi metal aqueous solution, the loadings of CoO, MoO3, and NiO in the hydrogenation catalyst CAT-5 are 2.5%, 15.0%, and 1.5%, respectively.

[0084] All other conditions remain unchanged.

[0085] Example 6

[0086] This embodiment is basically the same as Embodiment 1, except that:

[0087] In step 1), 3g of citric acid is dissolved in 90g of deionized water, and then 3g of nitric acid is added. The mixture is stirred until homogeneous and set aside for later use. 100g of boehmite, 10g of silica sol, and 3g of guar gum powder are placed in a crucible and stirred until homogeneous to obtain a powder. The prepared solution is slowly added to the powder while stirring until homogeneous to obtain a wet mixture. The wet mixture is extruded into clover-shaped strips with a diameter of 1.8mm (Φ1.8), and then subjected to a first drying process to obtain alumina carrier intermediate SRZ-1. The first drying temperature is 120℃ and the first drying time is 4h.

[0088] Alumina carrier SR-3 was prepared according to step 2) in Example 1;

[0089] The hydrogenation catalyst CAT-6 was then prepared according to step 3) of Example 1. During this process, by controlling factors such as the concentration of metals in the CoMoNi aqueous solution, the loadings of CoO, MoO3, and NiO in the hydrogenation catalyst CAT-6 were 2.5%, 15.0%, and 1.5%, respectively. The CoMoNi aqueous solution was prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, and water.

[0090] Example 7

[0091] This embodiment is basically the same as Embodiment 1, except that:

[0092] In step 1), 3g of citric acid is dissolved in 90g of deionized water, and then 3g of nitric acid is added. The mixture is stirred until homogeneous and set aside for later use. 100g of boehmite, 10g of silica sol, and 3g of guar gum powder are placed in a crucible and stirred until homogeneous to obtain a powder. The prepared solution is slowly added to the powder while stirring until homogeneous to obtain a wet mixture. The wet mixture is extruded into clover-shaped strips with a diameter of 1.8mm (Φ1.8), and then subjected to a first drying process to obtain alumina carrier intermediate SRZ-2. The first drying temperature is 100℃ and the first drying time is 6h.

[0093] In step 2), 22g of ammonium bicarbonate is dissolved in 200mL of water under stirring to obtain an ammonium bicarbonate aqueous solution with a mass percentage of 10%. 50g of alumina carrier intermediate SRZ-2 is immersed in 180g of the above ammonium bicarbonate aqueous solution for heat treatment (i.e., the mass ratio of the ammonium bicarbonate aqueous solution to the mass of the alumina carrier intermediate is 3.6:1). After the heat-treated material is cooled to room temperature, it is filtered. The filtered solid material is then subjected to a second drying and a first calcination to obtain alumina carrier SR-4. The heat treatment temperature is 80℃ and the heat treatment time is 4h. The second drying temperature is 100℃ and the second drying time is 6h. The first calcination temperature is 300℃ and the first calcination time is 6h.

[0094] The hydrogenation catalyst CAT-7 was then prepared according to step 3) of Example 1. During this process, by controlling factors such as the concentration of metals in the CoMoNi aqueous solution, the loadings of CoO, MoO3, and NiO in the hydrogenation catalyst CAT-7 were 2.5%, 15.0%, and 1.5%, respectively. The CoMoNi aqueous solution was prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, and water.

[0095] Example 8

[0096] This embodiment is basically the same as Embodiment 1, except that:

[0097] In step 1), 3g of citric acid is dissolved in 70g of deionized water, and then 3g of nitric acid is added and stirred until homogeneous to obtain solution 1. 1g of ammonium fluoroborate is dissolved in 20g of deionized water and stirred until completely dissolved to obtain solution 2. 100g of boehmite and 3g of guar gum powder are placed in a crucible and stirred until homogeneous to obtain powder. Solution 1 is slowly added to the powder while stirring until homogeneous to obtain wet mixture 1. Solution 2 is then slowly added to wet mixture 1 and stirred until homogeneous to obtain wet mixture 2. Wet mixture 2 is extruded into clover-shaped strips with a diameter of 1.8mm (Φ1.8) and then subjected to a first drying process to obtain alumina carrier intermediate SRZ-3. The first drying temperature is 100℃ and the first drying time is 6 hours.

[0098] In step 2), 18g of ammonium bicarbonate is dissolved in 100mL of water under stirring to obtain an ammonium bicarbonate aqueous solution with a mass percentage of 15%. 50g of alumina carrier intermediate SRZ-3 is immersed in 65g of the above ammonium bicarbonate aqueous solution for heat treatment (i.e., the mass ratio of the ammonium bicarbonate aqueous solution to the mass of the alumina carrier intermediate is 1.3:1). After the heat-treated material is cooled to room temperature, it is filtered. The filtered solid material is then subjected to a second drying and a first calcination to obtain alumina carrier SR-5. The heat treatment temperature is 80℃ and the heat treatment time is 10h. The second drying temperature is 110℃ and the second drying time is 5h. The first calcination temperature is 400℃ and the first calcination time is 5h.

[0099] The hydrogenation catalyst CAT-8 was then prepared according to step 3) of Example 1. During this process, by controlling factors such as the concentration of metals in the CoMoNi aqueous solution, the loadings of CoO, MoO3, and NiO in the hydrogenation catalyst CAT-8 were 2.5%, 15.0%, and 1.5%, respectively. The CoMoNi aqueous solution was prepared using basic cobalt carbonate, citric acid, MoO3, phosphoric acid, basic nickel carbonate, and water.

[0100] Comparative Examples 1-2

[0101] Comparative Example 1

[0102] This comparative example is basically the same as Example 1, except that:

[0103] In step 2), the alumina support intermediate SRZ-0 is directly subjected to a first calcination to obtain alumina support SR-6; wherein the first calcination temperature is 500℃ and the first calcination time is 4h; that is, the alumina support intermediate SRZ-0 is not treated with ammonium bicarbonate aqueous solution.

[0104] All other conditions remain unchanged.

[0105] In the hydrogenation catalyst DB-1 of Comparative Example 1, the loadings of CoO, MoO3, and NiO were 2.5%, 15.0%, and 1.5%, respectively.

[0106] Comparative Example 2

[0107] This comparative example is basically the same as Example 6, except that:

[0108] In step 2), the alumina support intermediate SRZ-1 is directly subjected to a first calcination to obtain alumina support SR-7; wherein, the temperature of the first calcination is 500℃ and the time of the first calcination is 4h; that is, the alumina support intermediate SRZ-1 is not treated with ammonium bicarbonate aqueous solution; other conditions remain unchanged.

[0109] In the hydrogenation catalyst DB-2 of Comparative Example 2, the loadings of CoO, MoO3, and NiO were 2.5%, 15.0%, and 1.5%, respectively.

[0110] Test case

[0111] The following parameters of the above embodiments and comparative examples were tested:

[0112] 1) Surface area S of hydrogenation catalyst BET Specific pore volume V: determined by physical adsorption method;

[0113] 2) The hydrogenation catalyst CAT-1 of Example 1 and the hydrogenation catalyst DB-1 of Comparative Example 1 were characterized by scanning electron microscopy (SEM). The results are shown in the figure. Figure 1 , Figure 2 , Figure 3 ;

[0114] 3) Evaluation of the desulfurization and denitrification performance of the hydrogenation catalyst: The desulfurization and denitrification performance of the hydrogenation catalyst was evaluated using a 20 mL pilot-scale hydrogenation evaluation apparatus. The catalyst loading was 20 mL. Straight-run naphtha was used as feedstock. The sulfur and nitrogen contents of the naphtha were analyzed according to ASTM D5453 and ASTM D5762, respectively. The results showed a sulfur content of 901 μg / g and a nitrogen content of 51.43 μg / g. Furthermore, the hydrogen partial pressure was 2.0 MPa, the hydrogen-to-oil volume ratio was 100:1, and the volume hourly space velocity (VHSV) was 4.0 h⁻¹. -1 The desulfurization and denitrification performance of the hydrogenation catalyst was evaluated by testing the reaction temperature during the treatment of the above straight-run naphtha with the hydrogenation catalyst, as well as the sulfur and nitrogen content in the refined naphtha obtained after treatment.

[0115] Test results

[0116] Table 1. Specific surface area, specific pore volume, desulfurization and denitrification performance of hydrogenation catalysts

[0117]

[0118] Data Analysis:

[0119] As shown in the table above, the specific pore volume and specific surface area (BET) of the hydrogenation catalysts CAT-1 to CAT-10 in each embodiment are higher than those of the comparative examples. Furthermore, the metal loading of the hydrogenation catalysts CAT-1, CAT-5, and CAT-6 is the same as that of the hydrogenation catalysts DB-1 in Comparative Example 1 and DB-2 in Comparative Example 2, indicating that the hydrothermally modified hydrogenation catalyst (support) of ammonium bicarbonate has a higher specific surface area.

[0120] from Figure 1 It can be seen that the cross-section of the hydrogenation catalyst CAT-1 in Example 1 is flat and uniform, and no active phase aggregation is observed. Figure 2 In the electron microscope image of the hydrogenation catalyst CAT-1, magnified to 50,000x, it can be seen that the active phase clusters are at the nanoscale, indicating that the active phase of the hydrogenation catalyst CAT-1 is more uniformly dispersed; the electron microscope images of the hydrogenation catalysts in other embodiments are similar to those of the hydrogenation catalyst in Example 1; from Figure 3 It can be seen that the hydrogenation catalyst DB-1 of Comparative Example 1 exhibits micron-sized active phase clusters on its surface;

[0121] In the process of processing straight-run naphtha, when the reaction temperature of the hydrogenation catalysts in each embodiment was between 276 and 283°C, the sulfur content in the refined naphtha was less than 0.5 μg / g and the nitrogen content was less than 0.3 μg / g. The hydrogenation catalysts of Comparative Examples 1-2 (hydrogenation catalysts prepared from a support without hydrothermal modification of ammonium bicarbonate) had reaction temperatures higher than 290°C when processing straight-run naphtha and making the above-mentioned refined naphtha meet the standards. It can be seen that the hydrogenation catalysts in each embodiment have excellent desulfurization and denitrification performance.

[0122] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a hydrogenation catalyst, characterized in that, include: After mixing and molding the alumina raw material with the molding aid, the material is first dried to obtain the alumina carrier intermediate. The alumina carrier intermediate is immersed in an ammonium bicarbonate aqueous solution for heat treatment, and then the heat-treated material is filtered. The filtered solid material is then subjected to a second drying and a first calcination to obtain the alumina carrier. The heat treatment temperature is 70-90°C and the heat treatment time is 4-10 hours. The alumina support is immersed in an aqueous metal solution, and then subjected to a third drying and a second calcination to obtain the hydrogenation catalyst.

2. The preparation method according to claim 1, characterized in that, The alumina raw material includes boehmite; And / or, the mass percentage of ammonium bicarbonate in the ammonium bicarbonate aqueous solution is 10% to 18%; And / or, the mass ratio of the ammonium bicarbonate aqueous solution to the mass of the alumina pre-carrier intermediate is (1.3 to 3.6):

1.

3. The preparation method according to claim 1, characterized in that, The molding aid includes one or more of a binder, an extrusion aid, and a modifier, wherein the binder includes one or more of nitric acid, acetic acid, and oxalic acid, the extrusion aid includes guar gum powder, and the modifier includes one or more of ammonium fluoroborate, phosphoric acid, and silica sol.

4. The preparation method according to claim 1, characterized in that, The temperature of the first drying is 100-120°C, and the drying time is 4-6 hours; And / or, the temperature of the second drying is 100-120°C, and the time of the second drying is 4-6 hours; And / or, the temperature of the third drying is 100-120°C, and the time of the third drying is 4-6 hours; And / or, the temperature of the first calcination is 300-600°C, and the time of the first calcination is 4-6 hours; And / or, the temperature of the second roasting is 300-600°C, and the time of the second roasting is 4-6 hours.

5. The preparation method according to claim 1, characterized in that, The process of immersing the alumina intermediate in an aqueous metal solution includes: immersing the alumina intermediate in an equal volume of the aqueous metal solution; And / or, the aqueous metal solution includes one or more of nickel, cobalt, molybdenum, and tungsten.

6. A hydrogenation catalyst, characterized in that, The hydrogenation catalyst is obtained according to the preparation method according to any one of claims 1-5.

7. The hydrogenation catalyst according to claim 6, characterized in that, The specific surface area of ​​the hydrogenation catalyst is 250–290 m². 2 / g, specific pore volume is 0.43~0.50cm³ 3 / g.

8. The hydrogenation catalyst according to claim 6 or 7, characterized in that, In the hydrogenation catalyst, based on metal oxides, the mass percentage of cobalt is 1.5% to 3.0%, the mass percentage of molybdenum is 5.0% to 17.0%, the mass percentage of nickel is 1.0% to 5.0%, and the mass percentage of tungsten is 10.0% to 15.0%.

9. The use of a hydrotreating catalyst according to any one of claims 6-8 in the hydrotreating of oil products.

10. The application according to claim 9, characterized in that, The oil contains a nitrogen content greater than or equal to 5 μg / g and a sulfur content greater than or equal to 600 μg / g.

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